[Case of CNS-limited ANCA-associated vasculitis presenting as recurrent ischemic stroke].

A 73-year-old man was admitted to our hospital because of a decrease in spontaneity. His medical history included two stroke episodes, probably related to hypertension. Brain MRI on admission demonstrated acute infarction in the right caudate nucleus and left putamen. Intravenous infusion of a low molecular-weight heparin added to oral antiplatelets was started. Following admission, he developed a low grade fever and severe inflammatory reaction. The focus of infection was not evident, and none of the antibiotics tried were effective. Ten days after admission, he developed right hemiparesis, and an additional brain MRI showed new multiple infarctions. We also determined the presence of a high MPO-ANCA titer (57 EU), and we diagnosed the patient's condition to be ANCA-associated vasculitis (AAV). Steroid therapy improved his inflammatory reaction and stroke recurrence was not observed. We suggest that vasculitis should be considered as a potential risk factor for repeated small infarctions with fever of unknown origin, especially those of perforating artery territories.